hw/virtio-scsi.c

   1 /*
   2  * Virtio SCSI HBA
   3  *
   4  * Copyright IBM, Corp. 2010
   5  * Copyright Red Hat, Inc. 2011
   6  *
   7  * Authors:
   8  *   Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
   9  *   Paolo Bonzini      <pbonzini@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include "hw/virtio-scsi.h"
  17 #include "qemu/error-report.h"
  18 #include <hw/scsi.h>
  19 #include <hw/scsi-defs.h>
  20
  21 #define VIRTIO_SCSI_VQ_SIZE     128
  22 #define VIRTIO_SCSI_CDB_SIZE    32
  23 #define VIRTIO_SCSI_SENSE_SIZE  96
  24 #define VIRTIO_SCSI_MAX_CHANNEL 0
  25 #define VIRTIO_SCSI_MAX_TARGET  255
  26 #define VIRTIO_SCSI_MAX_LUN     16383
  27
  28 /* Response codes */
  29 #define VIRTIO_SCSI_S_OK                       0
  30 #define VIRTIO_SCSI_S_OVERRUN                  1
  31 #define VIRTIO_SCSI_S_ABORTED                  2
  32 #define VIRTIO_SCSI_S_BAD_TARGET               3
  33 #define VIRTIO_SCSI_S_RESET                    4
  34 #define VIRTIO_SCSI_S_BUSY                     5
  35 #define VIRTIO_SCSI_S_TRANSPORT_FAILURE        6
  36 #define VIRTIO_SCSI_S_TARGET_FAILURE           7
  37 #define VIRTIO_SCSI_S_NEXUS_FAILURE            8
  38 #define VIRTIO_SCSI_S_FAILURE                  9
  39 #define VIRTIO_SCSI_S_FUNCTION_SUCCEEDED       10
  40 #define VIRTIO_SCSI_S_FUNCTION_REJECTED        11
  41 #define VIRTIO_SCSI_S_INCORRECT_LUN            12
  42
  43 /* Controlq type codes.  */
  44 #define VIRTIO_SCSI_T_TMF                      0
  45 #define VIRTIO_SCSI_T_AN_QUERY                 1
  46 #define VIRTIO_SCSI_T_AN_SUBSCRIBE             2
  47
  48 /* Valid TMF subtypes.  */
  49 #define VIRTIO_SCSI_T_TMF_ABORT_TASK           0
  50 #define VIRTIO_SCSI_T_TMF_ABORT_TASK_SET       1
  51 #define VIRTIO_SCSI_T_TMF_CLEAR_ACA            2
  52 #define VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET       3
  53 #define VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET      4
  54 #define VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET   5
  55 #define VIRTIO_SCSI_T_TMF_QUERY_TASK           6
  56 #define VIRTIO_SCSI_T_TMF_QUERY_TASK_SET       7
  57
  58 /* Events.  */
  59 #define VIRTIO_SCSI_T_EVENTS_MISSED            0x80000000
  60 #define VIRTIO_SCSI_T_NO_EVENT                 0
  61 #define VIRTIO_SCSI_T_TRANSPORT_RESET          1
  62 #define VIRTIO_SCSI_T_ASYNC_NOTIFY             2
  63 #define VIRTIO_SCSI_T_PARAM_CHANGE             3
  64
  65 /* Reasons for transport reset event */
  66 #define VIRTIO_SCSI_EVT_RESET_HARD             0
  67 #define VIRTIO_SCSI_EVT_RESET_RESCAN           1
  68 #define VIRTIO_SCSI_EVT_RESET_REMOVED          2
  69
  70 /* SCSI command request, followed by data-out */
  71 typedef struct {
  72     uint8_t lun[8];              /* Logical Unit Number */
  73     uint64_t tag;                /* Command identifier */
  74     uint8_t task_attr;           /* Task attribute */
  75     uint8_t prio;
  76     uint8_t crn;
  77     uint8_t cdb[];
  78 } QEMU_PACKED VirtIOSCSICmdReq;
  79
  80 /* Response, followed by sense data and data-in */
  81 typedef struct {
  82     uint32_t sense_len;          /* Sense data length */
  83     uint32_t resid;              /* Residual bytes in data buffer */
  84     uint16_t status_qualifier;   /* Status qualifier */
  85     uint8_t status;              /* Command completion status */
  86     uint8_t response;            /* Response values */
  87     uint8_t sense[];
  88 } QEMU_PACKED VirtIOSCSICmdResp;
  89
  90 /* Task Management Request */
  91 typedef struct {
  92     uint32_t type;
  93     uint32_t subtype;
  94     uint8_t lun[8];
  95     uint64_t tag;
  96 } QEMU_PACKED VirtIOSCSICtrlTMFReq;
  97
  98 typedef struct {
  99     uint8_t response;
 100 } QEMU_PACKED VirtIOSCSICtrlTMFResp;
 101
 102 /* Asynchronous notification query/subscription */
 103 typedef struct {
 104     uint32_t type;
 105     uint8_t lun[8];
 106     uint32_t event_requested;
 107 } QEMU_PACKED VirtIOSCSICtrlANReq;
 108
 109 typedef struct {
 110     uint32_t event_actual;
 111     uint8_t response;
 112 } QEMU_PACKED VirtIOSCSICtrlANResp;
 113
 114 typedef struct {
 115     uint32_t event;
 116     uint8_t lun[8];
 117     uint32_t reason;
 118 } QEMU_PACKED VirtIOSCSIEvent;
 119
 120 typedef struct {
 121     uint32_t num_queues;
 122     uint32_t seg_max;
 123     uint32_t max_sectors;
 124     uint32_t cmd_per_lun;
 125     uint32_t event_info_size;
 126     uint32_t sense_size;
 127     uint32_t cdb_size;
 128     uint16_t max_channel;
 129     uint16_t max_target;
 130     uint32_t max_lun;
 131 } QEMU_PACKED VirtIOSCSIConfig;
 132
 133 typedef struct {
 134     VirtIODevice vdev;
 135     DeviceState *qdev;
 136     VirtIOSCSIConf *conf;
 137
 138     SCSIBus bus;
 139     uint32_t sense_size;
 140     uint32_t cdb_size;
 141     int resetting;
 142     bool events_dropped;
 143     VirtQueue *ctrl_vq;
 144     VirtQueue *event_vq;
 145     VirtQueue *cmd_vqs[0];
 146 } VirtIOSCSI;
 147
 148 typedef struct VirtIOSCSIReq {
 149     VirtIOSCSI *dev;
 150     VirtQueue *vq;
 151     VirtQueueElement elem;
 152     QEMUSGList qsgl;
 153     SCSIRequest *sreq;
 154     union {
 155         char                  *buf;
 156         VirtIOSCSICmdReq      *cmd;
 157         VirtIOSCSICtrlTMFReq  *tmf;
 158         VirtIOSCSICtrlANReq   *an;
 159     } req;
 160     union {
 161         char                  *buf;
 162         VirtIOSCSICmdResp     *cmd;
 163         VirtIOSCSICtrlTMFResp *tmf;
 164         VirtIOSCSICtrlANResp  *an;
 165         VirtIOSCSIEvent       *event;
 166     } resp;
 167 } VirtIOSCSIReq;
 168
 169 static inline int virtio_scsi_get_lun(uint8_t *lun)
 170 {
 171     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
 172 }
 173
 174 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
 175 {
 176     if (lun[0] != 1) {
 177         return NULL;
 178     }
 179     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
 180         return NULL;
 181     }
 182     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
 183 }
 184
 185 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
 186 {
 187     VirtIOSCSI *s = req->dev;
 188     VirtQueue *vq = req->vq;
 189     virtqueue_push(vq, &req->elem, req->qsgl.size + req->elem.in_sg[0].iov_len);
 190     qemu_sglist_destroy(&req->qsgl);
 191     if (req->sreq) {
 192         req->sreq->hba_private = NULL;
 193         scsi_req_unref(req->sreq);
 194     }
 195     g_free(req);
 196     virtio_notify(&s->vdev, vq);
 197 }
 198
 199 static void virtio_scsi_bad_req(void)
 200 {
 201     error_report("wrong size for virtio-scsi headers");
 202     exit(1);
 203 }
 204
 205 static void qemu_sgl_init_external(QEMUSGList *qsgl, struct iovec *sg,
 206                                    hwaddr *addr, int num)
 207 {
 208     qemu_sglist_init(qsgl, num, &dma_context_memory);
 209     while (num--) {
 210         qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
 211     }
 212 }
 213
 214 static void virtio_scsi_parse_req(VirtIOSCSI *s, VirtQueue *vq,
 215                                   VirtIOSCSIReq *req)
 216 {
 217     assert(req->elem.in_num);
 218     req->vq = vq;
 219     req->dev = s;
 220     req->sreq = NULL;
 221     if (req->elem.out_num) {
 222         req->req.buf = req->elem.out_sg[0].iov_base;
 223     }
 224     req->resp.buf = req->elem.in_sg[0].iov_base;
 225
 226     if (req->elem.out_num > 1) {
 227         qemu_sgl_init_external(&req->qsgl, &req->elem.out_sg[1],
 228                                &req->elem.out_addr[1],
 229                                req->elem.out_num - 1);
 230     } else {
 231         qemu_sgl_init_external(&req->qsgl, &req->elem.in_sg[1],
 232                                &req->elem.in_addr[1],
 233                                req->elem.in_num - 1);
 234     }
 235 }
 236
 237 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
 238 {
 239     VirtIOSCSIReq *req;
 240     req = g_malloc(sizeof(*req));
 241     if (!virtqueue_pop(vq, &req->elem)) {
 242         g_free(req);
 243         return NULL;
 244     }
 245
 246     virtio_scsi_parse_req(s, vq, req);
 247     return req;
 248 }
 249
 250 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
 251 {
 252     VirtIOSCSIReq *req = sreq->hba_private;
 253     uint32_t n = virtio_queue_get_id(req->vq) - 2;
 254
 255     assert(n < req->dev->conf->num_queues);
 256     qemu_put_be32s(f, &n);
 257     qemu_put_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 258 }
 259
 260 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
 261 {
 262     SCSIBus *bus = sreq->bus;
 263     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 264     VirtIOSCSIReq *req;
 265     uint32_t n;
 266
 267     req = g_malloc(sizeof(*req));
 268     qemu_get_be32s(f, &n);
 269     assert(n < s->conf->num_queues);
 270     qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
 271     virtio_scsi_parse_req(s, s->cmd_vqs[n], req);
 272
 273     scsi_req_ref(sreq);
 274     req->sreq = sreq;
 275     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 276         int req_mode =
 277             (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 278
 279         assert(req->sreq->cmd.mode == req_mode);
 280     }
 281     return req;
 282 }
 283
 284 static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 285 {
 286     SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf->lun);
 287     SCSIRequest *r, *next;
 288     BusChild *kid;
 289     int target;
 290
 291     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
 292     req->resp.tmf->response = VIRTIO_SCSI_S_OK;
 293
 294     switch (req->req.tmf->subtype) {
 295     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
 296     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
 297         if (!d) {
 298             goto fail;
 299         }
 300         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 301             goto incorrect_lun;
 302         }
 303         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 304             VirtIOSCSIReq *cmd_req = r->hba_private;
 305             if (cmd_req && cmd_req->req.cmd->tag == req->req.tmf->tag) {
 306                 break;
 307             }
 308         }
 309         if (r) {
 310             /*
 311              * Assert that the request has not been completed yet, we
 312              * check for it in the loop above.
 313              */
 314             assert(r->hba_private);
 315             if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
 316                 /* "If the specified command is present in the task set, then
 317                  * return a service response set to FUNCTION SUCCEEDED".
 318                  */
 319                 req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 320             } else {
 321                 scsi_req_cancel(r);
 322             }
 323         }
 324         break;
 325
 326     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
 327         if (!d) {
 328             goto fail;
 329         }
 330         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 331             goto incorrect_lun;
 332         }
 333         s->resetting++;
 334         qdev_reset_all(&d->qdev);
 335         s->resetting--;
 336         break;
 337
 338     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
 339     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
 340     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
 341         if (!d) {
 342             goto fail;
 343         }
 344         if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
 345             goto incorrect_lun;
 346         }
 347         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
 348             if (r->hba_private) {
 349                 if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
 350                     /* "If there is any command present in the task set, then
 351                      * return a service response set to FUNCTION SUCCEEDED".
 352                      */
 353                     req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
 354                     break;
 355                 } else {
 356                     scsi_req_cancel(r);
 357                 }
 358             }
 359         }
 360         break;
 361
 362     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
 363         target = req->req.tmf->lun[1];
 364         s->resetting++;
 365         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
 366              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
 367              if (d->channel == 0 && d->id == target) {
 368                 qdev_reset_all(&d->qdev);
 369              }
 370         }
 371         s->resetting--;
 372         break;
 373
 374     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
 375     default:
 376         req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
 377         break;
 378     }
 379
 380     return;
 381
 382 incorrect_lun:
 383     req->resp.tmf->response = VIRTIO_SCSI_S_INCORRECT_LUN;
 384     return;
 385
 386 fail:
 387     req->resp.tmf->response = VIRTIO_SCSI_S_BAD_TARGET;
 388 }
 389
 390 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 391 {
 392     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 393     VirtIOSCSIReq *req;
 394
 395     while ((req = virtio_scsi_pop_req(s, vq))) {
 396         int out_size, in_size;
 397         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 398             virtio_scsi_bad_req();
 399             continue;
 400         }
 401
 402         out_size = req->elem.out_sg[0].iov_len;
 403         in_size = req->elem.in_sg[0].iov_len;
 404         if (req->req.tmf->type == VIRTIO_SCSI_T_TMF) {
 405             if (out_size < sizeof(VirtIOSCSICtrlTMFReq) ||
 406                 in_size < sizeof(VirtIOSCSICtrlTMFResp)) {
 407                 virtio_scsi_bad_req();
 408             }
 409             virtio_scsi_do_tmf(s, req);
 410
 411         } else if (req->req.tmf->type == VIRTIO_SCSI_T_AN_QUERY ||
 412                    req->req.tmf->type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
 413             if (out_size < sizeof(VirtIOSCSICtrlANReq) ||
 414                 in_size < sizeof(VirtIOSCSICtrlANResp)) {
 415                 virtio_scsi_bad_req();
 416             }
 417             req->resp.an->event_actual = 0;
 418             req->resp.an->response = VIRTIO_SCSI_S_OK;
 419         }
 420         virtio_scsi_complete_req(req);
 421     }
 422 }
 423
 424 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
 425                                          size_t resid)
 426 {
 427     VirtIOSCSIReq *req = r->hba_private;
 428     uint32_t sense_len;
 429
 430     req->resp.cmd->response = VIRTIO_SCSI_S_OK;
 431     req->resp.cmd->status = status;
 432     if (req->resp.cmd->status == GOOD) {
 433         req->resp.cmd->resid = tswap32(resid);
 434     } else {
 435         req->resp.cmd->resid = 0;
 436         sense_len = scsi_req_get_sense(r, req->resp.cmd->sense,
 437                                        VIRTIO_SCSI_SENSE_SIZE);
 438         req->resp.cmd->sense_len = tswap32(sense_len);
 439     }
 440     virtio_scsi_complete_req(req);
 441 }
 442
 443 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 444 {
 445     VirtIOSCSIReq *req = r->hba_private;
 446
 447     return &req->qsgl;
 448 }
 449
 450 static void virtio_scsi_request_cancelled(SCSIRequest *r)
 451 {
 452     VirtIOSCSIReq *req = r->hba_private;
 453
 454     if (!req) {
 455         return;
 456     }
 457     if (req->dev->resetting) {
 458         req->resp.cmd->response = VIRTIO_SCSI_S_RESET;
 459     } else {
 460         req->resp.cmd->response = VIRTIO_SCSI_S_ABORTED;
 461     }
 462     virtio_scsi_complete_req(req);
 463 }
 464
 465 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 466 {
 467     req->resp.cmd->response = VIRTIO_SCSI_S_FAILURE;
 468     virtio_scsi_complete_req(req);
 469 }
 470
 471 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
 472 {
 473     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 474     VirtIOSCSIReq *req;
 475     int n;
 476
 477     while ((req = virtio_scsi_pop_req(s, vq))) {
 478         SCSIDevice *d;
 479         int out_size, in_size;
 480         if (req->elem.out_num < 1 || req->elem.in_num < 1) {
 481             virtio_scsi_bad_req();
 482         }
 483
 484         out_size = req->elem.out_sg[0].iov_len;
 485         in_size = req->elem.in_sg[0].iov_len;
 486         if (out_size < sizeof(VirtIOSCSICmdReq) + s->cdb_size ||
 487             in_size < sizeof(VirtIOSCSICmdResp) + s->sense_size) {
 488             virtio_scsi_bad_req();
 489         }
 490
 491         if (req->elem.out_num > 1 && req->elem.in_num > 1) {
 492             virtio_scsi_fail_cmd_req(req);
 493             continue;
 494         }
 495
 496         d = virtio_scsi_device_find(s, req->req.cmd->lun);
 497         if (!d) {
 498             req->resp.cmd->response = VIRTIO_SCSI_S_BAD_TARGET;
 499             virtio_scsi_complete_req(req);
 500             continue;
 501         }
 502         req->sreq = scsi_req_new(d, req->req.cmd->tag,
 503                                  virtio_scsi_get_lun(req->req.cmd->lun),
 504                                  req->req.cmd->cdb, req);
 505
 506         if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
 507             int req_mode =
 508                 (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
 509
 510             if (req->sreq->cmd.mode != req_mode ||
 511                 req->sreq->cmd.xfer > req->qsgl.size) {
 512                 req->resp.cmd->response = VIRTIO_SCSI_S_OVERRUN;
 513                 virtio_scsi_complete_req(req);
 514                 continue;
 515             }
 516         }
 517
 518         n = scsi_req_enqueue(req->sreq);
 519         if (n) {
 520             scsi_req_continue(req->sreq);
 521         }
 522     }
 523 }
 524
 525 static void virtio_scsi_get_config(VirtIODevice *vdev,
 526                                    uint8_t *config)
 527 {
 528     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 529     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 530
 531     stl_raw(&scsiconf->num_queues, s->conf->num_queues);
 532     stl_raw(&scsiconf->seg_max, 128 - 2);
 533     stl_raw(&scsiconf->max_sectors, s->conf->max_sectors);
 534     stl_raw(&scsiconf->cmd_per_lun, s->conf->cmd_per_lun);
 535     stl_raw(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
 536     stl_raw(&scsiconf->sense_size, s->sense_size);
 537     stl_raw(&scsiconf->cdb_size, s->cdb_size);
 538     stw_raw(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
 539     stw_raw(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
 540     stl_raw(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
 541 }
 542
 543 static void virtio_scsi_set_config(VirtIODevice *vdev,
 544                                    const uint8_t *config)
 545 {
 546     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 547     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 548
 549     if ((uint32_t) ldl_raw(&scsiconf->sense_size) >= 65536 ||
 550         (uint32_t) ldl_raw(&scsiconf->cdb_size) >= 256) {
 551         error_report("bad data written to virtio-scsi configuration space");
 552         exit(1);
 553     }
 554
 555     s->sense_size = ldl_raw(&scsiconf->sense_size);
 556     s->cdb_size = ldl_raw(&scsiconf->cdb_size);
 557 }
 558
 559 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 560                                          uint32_t requested_features)
 561 {
 562     return requested_features;
 563 }
 564
 565 static void virtio_scsi_reset(VirtIODevice *vdev)
 566 {
 567     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 568
 569     s->resetting++;
 570     qbus_reset_all(&s->bus.qbus);
 571     s->resetting--;
 572
 573     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
 574     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 575     s->events_dropped = false;
 576 }
 577
 578 /* The device does not have anything to save beyond the virtio data.
 579  * Request data is saved with callbacks from SCSI devices.
 580  */
 581 static void virtio_scsi_save(QEMUFile *f, void *opaque)
 582 {
 583     VirtIOSCSI *s = opaque;
 584     virtio_save(&s->vdev, f);
 585 }
 586
 587 static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
 588 {
 589     VirtIOSCSI *s = opaque;
 590     int ret;
 591
 592     ret = virtio_load(&s->vdev, f);
 593     if (ret) {
 594         return ret;
 595     }
 596     return 0;
 597 }
 598
 599 static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 600                                    uint32_t event, uint32_t reason)
 601 {
 602     VirtIOSCSIReq *req = virtio_scsi_pop_req(s, s->event_vq);
 603     VirtIOSCSIEvent *evt;
 604     int in_size;
 605
 606     if (!(s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 607         return;
 608     }
 609
 610     if (!req) {
 611         s->events_dropped = true;
 612         return;
 613     }
 614
 615     if (req->elem.out_num || req->elem.in_num != 1) {
 616         virtio_scsi_bad_req();
 617     }
 618
 619     if (s->events_dropped) {
 620         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 621         s->events_dropped = false;
 622     }
 623
 624     in_size = req->elem.in_sg[0].iov_len;
 625     if (in_size < sizeof(VirtIOSCSIEvent)) {
 626         virtio_scsi_bad_req();
 627     }
 628
 629     evt = req->resp.event;
 630     memset(evt, 0, sizeof(VirtIOSCSIEvent));
 631     evt->event = event;
 632     evt->reason = reason;
 633     if (!dev) {
 634         assert(event == VIRTIO_SCSI_T_NO_EVENT);
 635     } else {
 636         evt->lun[0] = 1;
 637         evt->lun[1] = dev->id;
 638
 639         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
 640         if (dev->lun >= 256) {
 641             evt->lun[2] = (dev->lun >> 8) | 0x40;
 642         }
 643         evt->lun[3] = dev->lun & 0xFF;
 644     }
 645     virtio_scsi_complete_req(req);
 646 }
 647
 648 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 649 {
 650     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 651
 652     if (s->events_dropped) {
 653         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
 654     }
 655 }
 656
 657 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
 658 {
 659     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 660
 661     if (((s->vdev.guest_features >> VIRTIO_SCSI_F_CHANGE) & 1) &&
 662         dev->type != TYPE_ROM) {
 663         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
 664                                sense.asc | (sense.ascq << 8));
 665     }
 666 }
 667
 668 static void virtio_scsi_hotplug(SCSIBus *bus, SCSIDevice *dev)
 669 {
 670     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 671
 672     if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
 673         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
 674                                VIRTIO_SCSI_EVT_RESET_RESCAN);
 675     }
 676 }
 677
 678 static void virtio_scsi_hot_unplug(SCSIBus *bus, SCSIDevice *dev)
 679 {
 680     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
 681
 682     if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
 683         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
 684                                VIRTIO_SCSI_EVT_RESET_REMOVED);
 685     }
 686 }
 687
 688 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 689     .tcq = true,
 690     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
 691     .max_target = VIRTIO_SCSI_MAX_TARGET,
 692     .max_lun = VIRTIO_SCSI_MAX_LUN,
 693
 694     .complete = virtio_scsi_command_complete,
 695     .cancel = virtio_scsi_request_cancelled,
 696     .change = virtio_scsi_change,
 697     .hotplug = virtio_scsi_hotplug,
 698     .hot_unplug = virtio_scsi_hot_unplug,
 699     .get_sg_list = virtio_scsi_get_sg_list,
 700     .save_request = virtio_scsi_save_request,
 701     .load_request = virtio_scsi_load_request,
 702 };
 703
 704 VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf)
 705 {
 706     VirtIOSCSI *s;
 707     static int virtio_scsi_id;
 708     size_t sz;
 709     int i;
 710
 711     sz = sizeof(VirtIOSCSI) + proxyconf->num_queues * sizeof(VirtQueue *);
 712     s = (VirtIOSCSI *)virtio_common_init("virtio-scsi", VIRTIO_ID_SCSI,
 713                                          sizeof(VirtIOSCSIConfig), sz);
 714
 715     s->qdev = dev;
 716     s->conf = proxyconf;
 717
 718     /* TODO set up vdev function pointers */
 719     s->vdev.get_config = virtio_scsi_get_config;
 720     s->vdev.set_config = virtio_scsi_set_config;
 721     s->vdev.get_features = virtio_scsi_get_features;
 722     s->vdev.reset = virtio_scsi_reset;
 723
 724     s->ctrl_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 725                                    virtio_scsi_handle_ctrl);
 726     s->event_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 727                                    virtio_scsi_handle_event);
 728     for (i = 0; i < s->conf->num_queues; i++) {
 729         s->cmd_vqs[i] = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE,
 730                                          virtio_scsi_handle_cmd);
 731     }
 732
 733     scsi_bus_new(&s->bus, dev, &virtio_scsi_scsi_info);
 734     if (!dev->hotplugged) {
 735         scsi_bus_legacy_handle_cmdline(&s->bus);
 736     }
 737
 738     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
 739                     virtio_scsi_save, virtio_scsi_load, s);
 740
 741     return &s->vdev;
 742 }
 743
 744 void virtio_scsi_exit(VirtIODevice *vdev)
 745 {
 746     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
 747     unregister_savevm(s->qdev, "virtio-scsi", s);
 748     virtio_cleanup(vdev);
 749 }